Convert PAR to 3MF in your application
3D InterOp is a CAD interoperability SDK that lets your software read PAR files and write 3MF, generating the 3MF mesh from the geometry it reads, with tessellation settings your application controls.
Spatial does not offer an online converter or a desktop conversion app. 3D InterOp is a component that software vendors embed in their own products.
- Reads Solid Edge part · Writes 3MF
- Exact geometry → triangle mesh
- C++ / C# APIs
PAR to 3MF at a glance
Solid Edge part stores exact geometry; 3MF stores triangles. The translation is a tessellation, and the settings you choose decide how close the mesh stays to the original.
| Solid Edge part (source) | 3MF (target) | |
|---|---|---|
| Full name | Solid Edge Part | 3D Manufacturing Format |
| Standard / owner | Siemens | 3MF Consortium, ISO/IEC 25422 |
| File extensions | .par | .3mf |
| Geometry | Exact B-Rep | Triangle mesh |
| Assemblies / structure | Part file | Objects and build items |
| 3D InterOp support | Read only | Read and write |
What's preserved, what changes
Here is what your application can expect to carry across from Solid Edge part to 3MF.
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Changes
Geometry is tessellatedThe exact Solid Edge part B-Rep is replaced by a triangle mesh, generated by 3D InterOp from the exact geometry it reads. Accuracy depends on the tessellation settings your application uses.
Why software vendors add PAR to 3MF conversion
Additive manufacturing
3MF is still the input most slicers and print services expect. Writing it lets your users send parts to print directly.
Mesh-based processing
Inspection, scan comparison and mesh-editing tools work on triangles. A mesh output gives them a model they can open anywhere.
Lightweight sharing
A mesh is simpler than the native CAD file and needs no CAD system to open.
Things to check before you ship
- Written 3MF versions: 3MF 1.1.
- The 3MF writer is available through the UConnect interface only.
- Supported PAR input: Solid Edge V18 to SE 2026.
- Test tessellation settings on your heaviest parts: finer meshes mean larger files.
- Validate a sample of translated files in the target system your users actually work with.
Working with Spatial was a real milestone for us: Thanks to the powerful 3DInterOp library, we were able to successfully bring our complex CAD-based solutions to the cloud while remaining flexible to meet individual customer requirements. For us, Spatial is not just a technology partner, but a true enabler of our product strategy.
Dr. Arno Michelis, Founder, Simus Systems
Read the Case StudyAbout the formats
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Source format
What is a PAR (.par) file?
A PAR file is a Siemens Solid Edge part. Solid Edge is built on the Parasolid kernel and stores sheet metal parts in PSM files and assemblies in ASM files.
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Target format
What is a 3MF (.3mf) file?
3MF is an open format for additive manufacturing, defined by the 3MF Consortium. It stores triangle meshes with units, colors and build information in a single package.
Frequently asked questions
3D InterOp tessellates the geometry it reads from PAR when it writes 3MF. Your application sets the tolerances, so it controls the trade-off between accuracy and file size.
The 3MF writer is available through the 3D InterOp UConnect interface.
Yes. If your application uses Parasolid, a Parasolid-based Solid Edge reader is available.
3D InterOp reads Solid Edge V18 to SE 2026.
3D InterOp writes 3MF 1.1.
No. 3D InterOp reads PAR but doesn’t write it. To send data back to Solid Edge users, write a neutral format they can import, such as STEP.
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Building software that needs to convert PAR to 3MF?
3D InterOp is an SDK that lets your application read Solid Edge part and write 3MF alongside 30+ CAD and BIM formats.